This invention relates to a header for a combine harvesting machine of the type which can be moved in a working direction across a field including a standing crop for cutting of the crop and feeding of the cut crop into the combine harvester for separation of grain.
The combine harvester conventionally comprises a harvester body which is mounted upon ground wheels for transportation of the body across the field. At the front of the body there is provided a feeder housing which is inclined upwardly from a lower end adjacent the ground to an upper end which constitutes the entry of the crop into the combine body. The feeder housing is generally a rectangular tubular body which contains a conveyor arrangement for transporting the cut crop along the tubular body toward the combine.
On the front end of the feeder housing is provided a flange and an attachment mechanism for mounting of a header on the feeder housing. The header can be of various designs suitable for cutting the standing crop over a width generally significantly wider than the combine body, transporting the cut crop inwardly and feeding it through an opening which coincides with the mouth of the feeder housing.
In most cases the header is fixed rigidly to the feeder housing for the purpose of providing an effective seal between the rear opening of the header and the front mouth of the feeder housing. The rigidly mounted header has become conventionally accepted and is to a great extent the only arrangement available for commercial sale.
The rigid mounting of the header on the feeder housing does have a number of problems particularly in that it remains fixed mounted to the combine body regardless of variations in ground level. It is necessary therefore for the operator to be constantly aware of ground level and to raise and lower the header as a whole in dependence upon ground level changes and also to steer the combine so that it approaches ground level changes in the most convenient manner.
In cases where the operator misjudges ground level and causes one end or the other of the header to engage the ground, various consequences can occur. In minor cases the header may gouge into the ground causing soil and stones to be lifted onto the header and to be carried into the combine with the crop. While this is not immediately catastrophic it can cause damage to the delicate equipment over the short or long term. In particularly serious cases the impact can be sufficient to cause damage to the header which may require down time for repair.
Even in cases where no errors are made, the extra effort on the operative by having to constantly vary the height of the header in dependence upon ground level is tiring and leads to reduction in efficiency.
Attempts have therefore been made to enable the header to, to some extent, float relative to the feeder housing. In one particular arrangement, the header is attached to the feeder housing by a circular connection arrangement which allows the header to rotate about an axis centrally of the circular connection. In this way a circular opening in the back of the header co-operates with a circular mouth of the feeder housing enabling the seal therebetween to remain constant despite the rotational movement of the header about the center of the circle. This arrangement is however unsatisfactory in that it requires a specific shape of feeder housing opening and also because it is limiting in the floating movement which can be accommodated.
Swathers which do not require the seal since they do not include a feeder housing but merely deposit the cut crop onto the ground in a swath often include a floating arrangement in which the header of the swather can rise and fall in dependence upon engagement of the header with the ground either by way of skids or by gauge wheels. In many cases the floating movement is provided by way of links which are pivotally connected to the header and to the front of the mounting arrangement with the links allowing the header to lift vertically and the links also having sufficient free play to allow rotation of the header as a whole about an axis forwardly of the direction of movement. This floating action generated by the vertical and pivotal movement has been found to be particularly effective in enabling the header to operate in the most effective manner with the least necessity for control by the operative. However, this arrangement has been considered to be unacceptable in terms of a combine where the seal between the header and the feeder housing is of paramount importance.
It is one object of the present invention, therefore, to provide an improved header for a combine harvester which can be mounted for floating movement on the feeder housing of the combine harvester and yet provides an effective seal between the header and the feeder housing to prevent loss of crop.
According to the invention, therefore, there is provided a header for a combine harvesting machine comprising a header frame, a mounting frame including means for mounting the mounting frame fixedly on the machine for transportation of the header frame in a working direction across a field including a standing crop to be harvested, said header frame including ends thereof extending outwardly to respective side of the mounting frame means mounting said header frame on said mounting frame for limited vertical movement of the header frame relative to the mounting frame and limited pivotal movement of the header frame relative to the mounting frame about an axis generally parallel to the working direction such that each end of the header frame can be lifted independently of movement of the other end of the header frame, a knife arrangement extending transversely across a front edge of the header frame for cutting the standing crop, means defining an opening rearwardly of the mounting frame through which the cut crop is guided to pass, ground engaging means on the header frame arranged to cause said vertical and pivotal movement of the header frame in dependence upon changes in ground height, means for transporting said cut crop inwardly from the ends of the header frame and for feeding said cut crop through said opening, and a flexible pan member arranged underneath said transporting means with a forward end thereof in engagement with said header frame at a position rearwardly of said knife arrangement and a rearward end thereof in engagement with said mounting frame, said vertical movement and pivotal movement of said header frame being accommodated by flexing of said pan.
The transporting means which move the crop from the ends of the header frame inwardly toward the opening can be constituted either by a draper arrangement or by a conventional auger screw arrangement. In both cases, the header frame is basically a rigid structure so that the lifting movement of the ends of the header frame in dependence upon ground height are accommodated by the movement of the header frame relative to the mounting frame.
The pan is preferably of a sheet metal material which is chosen to have sufficient strength to span the extent between its contact with the header frame and its contact with the mounting frame without drooping but is sufficiently flexible amount transverse axis to accommodate the movement of the header frame.
With the foregoing in view, and other advantages as will become apparent to those skilled in the art to which this invention relates as this specification proceeds, the invention is herein described by reference to the accompanying drawings forming a part hereof, which includes a description of the best mode known to the applicant and of the preferred typical embodiment of the principles of the present invention, in which: